Buying Guide to Humidifiers

A lack of humidity in the indoor air can quickly lead to uncomfortable conditions for you and your home. Low humidity is especially a problem during the winter months in constantly heated air, but it can also occur during hot weather when the air conditioner is on. Low humidity is more common in certain climates.

A quick solution to the low humidity problem is a humidifier, which is designed to emit moisture into the air, thereby restoring a more comfortable humidity level. If you're considering investing in one, you'll want to understand the various types and their capabilities.

How do you know if you need a humidifier?

If your home humidity level dips below 30 percent on a regular basis, you want a humidifier. Symptoms of low humidity for people include dry skin, chapped lips, sinus problems such as bloody noses, scratchy throats and dry coughs and breathing trouble. A sign of an overly dry environment for your home is static electricity, which can damage electronics. Overly dry air also dries out wooden furniture and flooring, causes wallpaper to peel and can damage houseplants.

Is it possible to over-humidify your home?

While it is possible to over-humidify your home, many humidifiers feature a humidistat that regulates a humidifier's output to maintain desired humidity levels. Ideally, you want your indoor humidity levels to fall between 35 to 45 percent. If humidity levels are higher than 50 percent, you will experience unfavorable conditions such as condensation on walls and windows, which can lead to the growth of molds, dust mites and bacteria.

The best way to ensure the humidity level in your home is satisfactory is with a hygrometer, which looks like a thermometer and measures the moisture level in the air.

What do you do for overly humid air in your home?

If you live in a moist climate and your humidity levels are more than 50 percent, instead consider purchasing a dehumidifier, which removes moisture from the air.

The best way to determine the right kind of humidifier is to address these questions: 1) do you have hard or soft water, 2) are you looking for a humidifier for a specific health concern, and 3) what is the room size you are going to put the humidifier in.

Do you have hard or soft water?

Soft water provides the easiest maintenance of a humidifier in that you rinse the unit with water and remove any deposits with a brush. Hard water leaves a more noticeable mineral residue/scale that is much harder to remove. Use distilled water instead.

Does someone in your household have a bad cold?

A humidifier may help to relieve congestion. By adding moisture to the air, it makes it easier for nasal passages to drain and a person with congestion to breathe.

What size is your room?

Before you shop, know your room size. Come prepared knowing the room's measurements. The packaging will state the suggested room coverage area in square feet.

Various types of portable humidifiers exist, each with specific advantages.

Types of Humidifiers

Type of Humidifier

How it Works

Best For

Ultrasonic Cool Mist or Ultrasonic Dual Cool/Warm Mist

Produces a fine mist by passing water through a nebulizer, which uses high frequency vibrations to transform the water into a fine mist that is circulated throughout the room by an internal fan.

Cool mist option is safe for use in children's rooms. Many possess an ionizer stick or built-in nano-silver technology that prevents and controls bacterial growth in the air. Quiet operation.

Evaporative Cool Mist

Pulls water through a filter or wick, removing mineral deposits and preventing bacteria from entering the air. A fan then blows air over the moistened wick, speeding the rate of evaporation. The result is a natural humidification.

Energy efficient and safe for homes with small children, because this type of unit contains no heating element. Cool mist is often beneficial for individuals suffering with allergies and asthma. Important to follow manufacturer cleaning instructions, as unheated water can promote the growth of bacteria and molds. Filter or wick requires periodic replacement.

Warm Mist

Machine boils water to kill bacteria and molds. The resulting steam becomes a fine mist that is released into the air, producing a warm mist that moistens and warms the room.

Can be used as a vaporizer to dispense medication into the air. Useful in cold climates, as it also warms the room. Hot water kills bacteria and molds and some models feature a UV bulb for extra water sterilization. Many models also have a humidistat that controls the humidity output.

Air Washer

Humidifies and purifies the air with the use of stacked disks in the machine that rotate in the water. When dry air comes in contact with the disks, evaporation occurs and the resulting mist is released from the machine into the air, increasing humidity. As dry air gets sucked into the machine, airborne contaminants are drawn into the water, where they stay.

Cleans and humidifies the air. Some models possess an automatic shutoff when the water tank is empty, which prevents the machine from dispelling unwanted mineral deposits into the air. Other models have refill warning lights. Requires no replacement filters. The washable disks are easy to clean.

What size humidifier should you buy?

Humidifiers come in a wide range of sizes - from small tabletop units to floor standing models. The size of the humidifier you buy is directly related to the size of the room you wish to humidify. Each humidifier features an output capacity best suited to humidify a certain size range of room.

How long will a humidifier run before you need to refill it?

This is determined by the water tank capacity. The longer a unit can run, the less you will need to fill it. Also you can set it to higher output, increasing the amount of mist you put out, so you may find a larger tank works best for you.

What else should you consider?

*Noise output. While some models are virtually silent, such as many of the ultrasonic models, others produce a white noise sound.

*Placement. Smaller humidifiers can be positioned on a tabletop or other flat surface, whereas larger models can often be located against the wall, providing that the discharge comes from the top. If not, such humidifiers must be placed away from the wall. Use special care in your placement of warm mist humidifiers, as the water they contain is very hot and can cause injury if the unit is knocked over.

* Decor style. Many humidifiers are utilitarian in appearance, but there are several models on the market appropriate for children's rooms, such as those fashioned to look like animals.

You might want to look for a model with one or more of these useful accessories.

The following accessories or product additions further enhance owning a humidifier.

In order to prevent the spread of bacteria and mold, cleanliness is important. Follow the manufacturer's instructions carefully on how to care for your particular humidifier model.

Cool mist models call for replacing the filter or wick every three months, whereas warm mist humidifiers require that you clean the heating element and the water chamber. The disks must be kept clean in airwashers.

For the best operation and longevity of the machine, it's important to keep the humidifier filled to the appropriate water level.